Grinding machinery



Dec. 22, 1936.

M. ROMAINE GRINDING MACHINERY Filed March 3, 1954 J72 J47 J71 J44 Illz'gr' 31 14 9 Sheets-Sheet 1 D -2 1936- M. ROMAINE GRINDING MACHINERY9 Sheets-Sheet 2 Filed March 3, 1934 Dec; 22, 1936. M R NE' 2,065,100

GRINDING MACHINERY.

Filed March 3, 1934 9 Sheets-Sheet 3 J03 301 21a 494 25} 29 ig 2 W I Wmmm M. ROMAINE GRINDING MACHINERY Dec. 22, 1936.

Filed March 3, 1934 9 Sheets-Sheet 4 Gum/MA;

Dec. 22, 1936. M N 2,065,100

GRINDING MACHINERY Filed March '3 1934 airman 9 Sheets-Sheet 5 Dec. 22,1936.

M. ROMAINE 2,065,100

GRINDING MACHINERY Filed March 3, 1934 9 Sheets-Sheet 6 Dc; 22, 1936.RQMAINE 2,065,100 I GRINDING MACHINERY Filed March 3, 1954 9Sheets-Sheet 7 am." My

VII/III/I/I/ GRINDING MACHINERY 9 Sheets-Sheet 8 Filed March 3, 1954Patented Dec. 22, 1936 UNITED STATES PATENT OFF-ICE GRINDING MACHINERYMillard'ltomaine, Cincinnati, Ohio, assignor to Cincinnati GrindersIncorporated, Cincinnati, Ohio, a corporation of Ohio Application March3, 1934, Serial No. 713,890

,, 29 Claims.

1 Another object of the invention is the provision semi-automatic,-cyclic manner for expeditiously producing such large work pieces.

A further object of the invention is the provir sion of improved meansfor effecting the operation of the machine and the control thereof whichinvolves the use of-hydraulically actuated means for expeditiouslyproducing the work.

A further object of the invention is the provision of an improvedcenterless grinder of the vertical or substantially vertical type inwhich the parts thereof are of massive construction and requiringadjustments thereof in a vertical direction and whereby the saidadjustments may be made with the expenditure of the least amount ofeffort.

A still further object of the invention is the provision of a centerlessgrinder of the kind above referred to wherein improved means areprovided for operating the feed mechanism of the machine.

Other objects and advantages of the present invention should be readilyapparent by reference to the following specification, considered inconjunction with the accompanying drawings forming a part thereof and itis to be understood that any modifications may be made in the exactstructural details there shown and described, within the scope of theappended claims, without departing from or exceeding the spirit of theinvention. 1

.Inthe drawings:

Figure 1 is a front elevation of the improved centerless grinder of thepresent invention.

Figure 2 is a top plan viewof the machine shown in Figure 1, certainoverhead parts of Figure 1 being eliminated.

Figure 3 is a vertical sectional view through the machine andillustrating certain of the operative parts thereof.

Figure 4 is a fragmentary sectional view taken on line 4-4 of Figure 1.Y

Figure 5 is a fragmentary sectional view taken on line 5--5 of Figure 3.

Figure6 is a. sectional view on line 6-6 of Figure 5.

of an improved centerless grinder operable in a Figure '7 is a viewpartly in elevation and partly in section illustrating the controlhandle for the machine as seen on line 'I-1 on Figurel.

Figure 8 is a sectional view taken substantially on line 88 of Figure-5.

Figure 9 is a sectional view taken on line 9-9 of Figure 5.

Figure 10 is a sectional view taken on line Ill-l0 of Figure 5.

Figure 11 is a view, partly in section and partly in plan, as seen fromline I l-|l of Figure 3.

Figure 12 is a sectional view taken on line l2l2 of Figure 11.

Figure 13 is a sectional view taken on line l3-l3 of Figure 12.

Figure 14 is a sectional view taken on line 14-44 of Figure 12.

I Figure 15 is a view taken substantially along the, axis of theregulating wheel spindle and illustrating the change speed mechanism.

' Figure 16 is a fragmentary view at right angles to Figure 15 as seenfrom line Iii-l6 on Figure 15.

Figure 17 is a sectional view taken on line l'l-l'i of Figure 15.

Figure 18 is a plan view of the work loading and ejecting mechanism asseen from line l8-l8 on Figure 1.

Figure '19-is a sectional view taken on line l9-l9 of Figure 18.

Figure 20 is a sectional view taken on line 20-20 of Figure 18.

Figure 21- is a sectional view taken on line 2I--2l of Figure5.

Figure 22 is a. diagrammatic view illustrating the hydraulic circuitinvolved in the invention.

Figure 23 is a fragmentary sectional view taken on line 23-43 of Figure3.

Throughout the several views of the drawings similar referencecharacters are employed to denote the same or similar parts.

As was noted above, this invention pertains to a centerless grinder .foroperating on or producing large work pieces and for grinding a pluralityor portions 'of a work piece concentrically.

' {The machine is semi-automatically operated, re-

quiring the operator to merely place a work piece in a work loadingcradle and insert in the grinding throat and then throw a lever forinitiating the cycle of the machine and upon completion of the cycle towithdraw the cradle and eject the .work therefrom.

The machine comprises a bed or base 26 from which rises a column 21, seeFigure 3. Mounted on top of the column 21 is the'grindingwheel supports29 and 30 to which are clamped as by' clamps 3| and 32 the journalbearings 33 and 34. The bearings 33 and 34 have rotatably mountedtherein a'spindle 35 to which are spaceably secured grinding wheels 36.Since the construction of the spindle and its supporting bearings formno part of the present invention it is not further illustrated ordescribed.

The said spindle 35 is driven through a pin and slot connection 31 by ashaft 38 journaled in a bracket 39 secured to the side of the column andwith the axis of the shaft substantially in line with the axis of thespindle. Secured to the spindle is a sheave or pulley 49 of the multiplegroove type about which is trained multiple V belts 4|. The. belts 4|are in turn trained about a pulley or sheave on the motor shaft 42 ofthe prime mover or motor 43. The drive, including the belts 4|, issuitably enclosed within a guard 44 secured to the side of the column.

Opposed to each. of the grinding wheels is a regulating wheel 45 securedto a spindle 46 by means of spacing sleeves 41. The regulating wheels 45and spacing sleeves 41 are clamped between a flange 48 integral with thespindle and a nut 49 threaded thereon. One end of the spindle isjournaled in a bearing 59 integral with a head 5|, the head 5| being inturn connected by a stud 52 to a bracket 53. The head 5| is thereforecapable of being adjusted to dispose the axis of the spindle 46 inangular relation to the axis of the grinding wheel spindle 35.

The end of the spindle 46 projecting beyond the collar 48 is reduced asat 54 where it is journaled in a housing 55, also integral with the head5|. Keyed or otherwise secured to the reduced portion 54 of the spindleis a worm wheel 56 in mesh with a worm 58 on the worm shaft 59. The wormshaft 59 is rotatably journaled in a bracket 59A which is mounted withinthe housing 55 for oscillation about the pivot shaft 69. From this itwill be seen that the worm 58 may be meshed with or disengaged from theworm wheel 56. Also, slid'ably keyed on the reduced portion 54 of thespindle is a clutch 6| having projecting from one face thereof clutchteeth 62 adapted to engage co-operating clutch teeth 63 on the adjacentface of a bevel gear 64 loosely mounted on the spindle portion 54. Theclutch 6| is provided with a. circumferential groove 65 in which isdisposed a shifter fork 66 integral with the bracket 59A. From this itwill be seen the relation of the shifter fork 66 to the worm 58 is suchthatwhcn the said worm .58 is meshed-with the worm wheel 56 the clutchteeth 62 and 63 are disengaged by shifting the clutch 6| to the positionshown in Figures 15 and 16, while the reverse actuation of the bracket59A to disengage the worm wheel 58 and worm 56 simultaneously engagesthe clutch teeth 62 and 63.

In order to effect the oscillation of the bracket 59A, it has dependingtherefrom an arm 67, the

end of which engages an eccentric pin 68 associated with an oscillatableshaft 69. The shaft 69 is journaled for oscillation in a suitablehearing provided by the housing 55 and projects be-.

- yond the said housing to' which projection is fastened the handle 19.From this it will be seen that through the operationbf the handle 19 thebracket 59A may be actuated for either engaging the clutch teeth 62 and63 or the worm and worm wheel 58 and 56.

Secured to the rear end of the worm shaft 59 is'a gear 1| meshingwithagear 12 carried by a stub shaft I3 rotatably journaled in bearingscarried by the housing 55 in a plane above the worm shaft 59. The stubshaft 13 has integral with or secured to its other end a gear I4 meshingwith the spur gear 15 of a multiple gear unit I6. The multiple gear unit16 has formed at one end thereof bevel gear 'l'l which meshes with thebevel gear 64 loosely journaled on the spindle and has formed at itsother end the gear 18 meshing with bevel gear pinion 19. The pinion 19is formed integral with or secured to drive shaft 89, also journaled insuitable bearings provided by the housing 55. The drive shaft 48 ex-'tends through and beyond the housing 55 where it is connected by acoupling 8| with the shaft 82 of the. motor or prime mover 83. The motoror prime mover 83 is carried by a suitable shelf or the like 84 integralwith the head 5|.

From the foregoing it will now be seen that the regulating wheel unit isa self-contained one and includes means whereby its spindle andregulating wheels may be driven at a relatively slow rate of speed whilecontrolling therate of rotation of the work or at a faster rate of speedduring v the truing of the wheels.

-The bracket 53 is integral with or secured to a slide 85 which hasformed on its under surface a dovetailed guide way 86. Received in theguide way 86 is a correspondingly shaped guide 81 formed on the upperface of a lower slide 88. The slide 85 is adapted to be shifted relativeto the slide 89 by means of. a screw 89 having its rear end suitablyjournaled in a bracket 99 secured to the lower slide 88. The threadedend of the screw 89 is connected to a nut 9| rotatably journaled insuitable bearings provided by the upper slide 85. The nut 9| is heldagainst any axial movement relative to the slide 85 and has formedintegral therewith or secured thereto a spiral gear 92. The said spiralgear 92 is in mesh with a complementary gear 93 on one end of a shaft 94and the said shaft 94 is journaled in suitable bearings in the bracket53 and projects therebeyond where the projecting end is given an angularcross section for a wrench or the like.

The lower slide 88 is provided onits under surface with a seconddovetailed guide 95 received in a correspondingly shaped guide way 96formed in the upper surface of a bed plate 91. -The slide 88 at itsinner'end is provided with a transverse guide way 98 receiving thetongue 99 of a block Hill. The block I00 carries at its upper end the-'work support or work rest blade |8| which has 'at a relatively slowwork controlling rate of speed also in a clockwise direction. From thisit follows that the opposed surfaces of the grinding and regulatingwheels travel in opposite directions with the grinding wheels operatingtoward the. work rest blade |9| while the regulating wheels operate awayfrom the said blade.

In practice the grinding wheels are subject to relatively rapid wear asis usual with wheels of this type wherefore the work rest blade andregulating wheels are periodically fed toward the grinding wheel. Forthis purpose the lower slide plate 91.

88 has secured to its under surface a housing I 04 in which is clamped anut I05. In threaded engagement with the nut I05 is an adjusting screwI06 whichhas one end thereof journaled in bearings I01 provided by thebed plate 91. The screw I06 projects beyond the bearings I01 and hassecured to its projecting end a bevel gear I08 in mesh with a secondbevel gear or pinion I09, see Figure 4, which bevel pinion I09 is keyedor otherwise secured to a shaft IIO rotatably journaled in suitablebearings provided by the bed also keyed or otherwise secured to it abevel pinion III meshing with a bevel-gear II2 on the inner end' of ashaft II 3. The shaft H3 is journaled in bearings provided by a housingII4 which also encloses the bevel gears III and II2 and is secured-tothe side of the base plate 91.

The shaft II3 extends beyond the housing II4 to receive the coarseinfeed hand wheel H5 and the finefeed or micrometer mechanism under thecontrol of the hand wheel and handle H6. The mechanisms operated by thehand wheels H5 and 6 are of a well known form and it is therefore deemedthat further description thereof is unnecessary.

In practice the actual feed of the work and wheel is affected byoscillating the base plate 91 and parts carried thereby toward thegrinding wheel. For this purpose the said base plate is provided at apoint beneath'the grinding wheels with lugs II1 through which pass apivoted shaft II8. The'shaft II8 also extends through a lug II9 integralwith and depending from a bracket I20. nected as by stud I 2| with thegrinding wheel head 28. The pivot I2I and bracket I20 are utilized forcorrecting misalignment of the axes of the grinding and regulating wheelspindles whereby the said spindles may be accurately adjusted to disposesame in parallelism. From the .foregoing it will now be seen that theregulating wheels are adapted to have their axes disposed at an angle tothe axis of. the grinding wheel spindle to effect a feed component onthe work. At the same time the said axes may be accurately adjusted asrespects parallelism thereof.

To effect the oscillation of the plate 91 and parts carried therebytoward the grinding wheel the said plate has pivotally connected to' itat I22 one end of link portion I23, the link portion I23 being in'turnconnected with link portion I24 pivotally connected at I25 with aplunger I26. The plunger is mounted for axial movement through a'sleeveI21 carried by bracket or housing I28 secured to the rear of the column21. The plunger I26 has rotatably mounted in its rear end a roller I29which contacts with the face ofa cam I30. The cam I30 is adapted to behydraulically actuated as will be later described. In order tocounterbalance the enormous weight .of the base plate 01 and partscarried thereby there is provided interiorly of the column 21 a weightI3I connected by a flexible member or cable I32 with the said base plate91 as at I33. The strap I32 passes over the periphery of a wheel orroller I34 idly rotatably supported in brackets I35 carried by thecolumn 21.

The infeed cam I30 is shown in plan in Figure 5 and. comprises a lowportion I36 followed by a rapid rise I31, a slow rise I38 and a plane orfiat portion I39. The cam.J30, while efiecting the relative feed,travels toward the right as seen in Figure 5 and therefore efiects arelatively rapid The other end of the shaft IIO has The bracket I20 inturn is pivotally con movement of the parts through the portion I31, aslow infeed through the portion I38 and a dwell through the portion I39topermit a sparking out of the work and the wheel. The cam I30 issecured to a carrier I40, see Figure 8, which is in turn connected tothe free end of a piston rod I4I which carries at its other end a pistonI42. The piston I42 is enclosed by a cylinder I43 which has at oppositeends piston heads I44 and 145, piston head I45 being provided with astuffing box I46 through which the piston rod passesv and prevents theescape of the medium from within the cylinder.

The piston I42 is adapted to be actuated relative to the cylinder by anhydraulic medium, preferably-oil, and the circuit for controlling theflow of the medium is shown most clearly in Figure 22. As there shown,the hydraulic system includes a sump or tank I41 which contains the oil.This tank I41 may be a separate independent unit attached to the machineor it may form a part of the supporting bed or column as is usualpractice. Disposed above the tank I41 is a power driven pump I48connected with ,the tank by a suction line or pipe I49. The pump I 48discharges the medium under pressure into a conduit or pipe I50 whichterminates in the starting and stopping valve indicated generally by thenumeral I5I and the conduit has extending therefrom a branch conduitconnected with the relief valve I52.

The starting and stopping valve I5I is shown structurally in Figure 9and as there shown comprises a valve bushing I52A pressed into a bore ina valve casing I53 carried by the housing I28;

The valve member I6I is connected by a hook connection I61 toa stem I68.The stem I68 is mounted in support ribs I69 integral with the housingl28 for axial movement relative thereto and to efiect the movement ofthe valve member I6I. The free end of the stem I68 is mounted in a guidesleeve I10 carried by the housing I28. The sleeve I10, in addition,encloses a spring I1I which abuts on one end with the stem I68 and onthe other end with a plug I12 which closes one end of the sleeve I10.The spring I1I is utilized for shifting the valve I6I in one direction,namely, to a stop position while the said valve is manually shifted toits second or open position and latched therein by means to be laterdescribed.

As was just noted, the valve member I6I is shifted to a right hand orrunning position by manual means which eiiects the starting of the cycleof operation of the machine and for this purpose the stem I68 isprovided with a reduced portion I13 formed between a collar I14 and thestem guide portion I15 which guide portion is disposed within the guidesleeve I10. A valve shifter member I16 is provided, having a bifurcatedend I11 whose arms straddle the reduced portion I13 of the stem and areadapted on oppo site sides thereof to engage the shoulders prostartingposition.

' between them the central Since when in this position the transversepin vided by the stem collar I 14 and guide portion I15. In other words,the valve shifter member I16 is actuated to the right, as seen in Figure9, against the yielding resistance of spring "I for correspondinglyshifting the valve to its openor To effect this shifting the shiftermember I16 is pinned or otherwise secured to the endof a rod I18 mountedfor sliding movement through a bearing sleeve I19 provided by housingI28 and additional bearings provided by a supplemental housing I80.Within the supplemental housing I80 the rod I128, see Figure 5, isprovided with nuts I8I and I82 which form abutments for the long arm I83of a bell crank lever I84. The lever I84 is pivotally mounted at I85withinthe supplemental housing I80 for oscillating movement relativethereto and the said lever has projecting on the other side of the pivotI85 its short arm I86. Pivotally connected to the free end of the shortarm I86 is a clevis I81 secured to the end of an angularly disposed. rodor bar I 88, see Figure 7. The rod I88 carries at its upper end a secondclevis I89 which is pivotally connected at I90 to a short lever I9Ikeyed or otherwise secured to an oscillatable shaft-I92. The shaft I92is oscillatably journaled in a bracket I93 secured to the outer face ofthe supplemental housing I80 and the said shaft extends beyond the saidhousing to which extending portion is secured the operating lever I94.

From the foregoing it will be noted that the lever I94 may be actuatedfor effecting the counterclockwise oscillation of the bell crank I84 asseen in Figure for causing'a shifting of the valve stem I18 to the rightas seen in Figures 5 and 9. This movement of the rod I18 through thevalve shifter I16 correspondingly shifts the valve stem I68 and valveI6I to an open or starting position. The handle I94 and bell crank I84,upon release thereof by the operator, when actuated in either direction,is returned to a neutral or central position. The mechanism foreffecting this return is illustrated in Figures 5 and 6 and comprises apin I95 extending transversely of one of the arms of the bell crank.I84. As shown in the drawings the pin passes through the short arm I88of the bell crank and the pin extends through elongatedperforations orslots formed in angle members I 98 and I91 which have respectivelyprojecting therefrom studs I98 and I99. Respectively encircling the saidstuds are coil springs 200 and NI which contact on one end with theirangle brackets I96 and I91 and on the other ends with the lateral wallsof the housing I80. The studs I98 and I99 are each provided with nuts202 for initially positioning the lever I84 and determining positionthereof.

I95 engages the opposite limits of the elongated perforations or slotsin the members I98 and I81 it is believed that the operation of thisstructure is evident from the drawings without a further descriptionthereof.

The valve member IGI and valve stem I68are locked in the open positionor during the cycle of operation of the machine and for this purpose thecollar I14 on the stem I68 has a shoulder 203 which co-operates with thenose 284 of a latch member 205. The latch 205 is pivotally mounted at205 within the housing I28. In order to shift the latch 205 to itslatching position it has connected therewith one end of a spring 201which has its other end anchored to a fixed part of the housing I28interiorly thereof, as seen for example in Figure 9.

The latch is adapted to be automatically released at the end of a givencycle by means to be' later described, and additionally the latch may bereleased by the handle I94 in case of an emergency. For this purpose therod I18 terminates closely adjacent the upper end of the latch 205 and.is provided with an adjustable abutment 208 here shown as a headed boltor.

.er I18 may be actuated through the handle I 94 to engage the adjacentshoulder of the collar I14 and thereby manually shift the valve to itsclosed position. It should be understood that in the normal operation ofthe machine the valve will automatically shift to its closed positionand the latch will be automatically tripped, the manual tripping andshifting of the valve just described being resorted to only in the caseof an emergency.

In order to automatically trip the latch it is provided in its upper endwith a cross slot or notch 209 receiving the ball end 2") of a lever 2IIkeyed or otherwise secured to one end of a shaft 2I3. The shaft 2I3 isjournaled for oscillation in a bearing sleeve 2I4 carried by a wall 2I5of the housing I28. The shaft 2I3 projects beyond the inner end of thesleeve 2I4 and has keyed or otherwise secured thereto a flipper dog 246.The flipper dog 2I8 overlies a stop dog 2I1 secured in a slot 2 I8formed in the upper surface of the carrier I40. The dog 2 I1 is locatedat the right hand end of the said carrier and since the carrier makesone reciprocationto the right for effecting the oscillation of the bedplate and parts carried thereby to reduce a work piece to the desiredsize and then a return reciprocation to its initial position the latchwill be released at the conclusion of a. complete cycle. In other words,the starting and stopping valve is manually opened to initiate a machinecycle and automatically shifted to stop the machine at the conclusion ofthis cycle.

When'the stop valve is shifted from the right hand or running positionto a position to the left of that indicated in Figures 9 and 22,pressure line I55 will then be connected by way of the cannelure I65 ofthe valve to port I 55 and thence through line '2I9, port I59 and theadjacent valve cannelure to port I58 and line 221. It will thus beevident that when the valve device has been moved to a stop position,preventing flow of the hydraulic actuating medium for eifecting cyclicshifting of the machine, that the fluid is then connectible by way ofthe lines and portings just referred to to conduit 221 leading to thetruing mechanism for actuation thereof. Accordingly the one valve servesalternatively to direct pressure either to the feed controllingmechanism or to the truing device, depending on the position adjustmentthereof. r

Continuing now the description of the hydraulic circuit as shown inFigure 22, it will be seen that the pressure conduit, I50 terminates atthe ports I55 of the starting and stopping valve bushing I 52A, whilethe ports I56 and I 59 have connected therewith one end of branchconduits 2I9 and 220, the latter of which empties into the tank or sumpI41. Included in the conduit 222 that terminates at its other end in areversing valve mechanism indicated generally'by the numeral 223, whilethe ports I51 have connected therewith one end of a pipe or conduit 224,which terminates at its other end in the pilot reversing valve mechanismindicated gen-- erally by the numeral 225 and the 'sa'id'conduit 224also terminates througha branch conduit or pipe'226 in thereversingvalve mechanism 223. The ports I58 of the starting and stoppingvalve 'I5I have connected therewith one end of a pipe or conduit 221which terminates at its other end in the control mechanism for operaating the truing mechanisms for the grinding and regulating wheels aswill be described in detail later.

Thepilot and reversing valve mechanisms are in practice mounted in axialalignment in the valve casing I53 and for convenience are disposedabovethe starting and stopping valve mechanism I5I as shown in Figure 9.These valves are independent mechanisms, the reversing valve beingoperated. by pressure under the control of the pilot valve which in turnis controlled by suitable dogs. As shown in Figure 9, the reversingvalve mechanism 223 comprises a valve bushing 228 through which isformed a plurality of sets of radial ports 229, 230, 231, 232, 233, 234and 235,

each set being encircled by a similar CiI'ClllnfelGD-' tial groove 236formed in, the exterior of the bushing 228. Within the bore in thebushing 228 is the reversing valve member 231 having formed thereonpistonportions 238, 239 and 240 forming between them cannelures 24I and242 which connect the sets of radial ports in different combinationsdepending upon the position of the valve member.

The pilot valve mechanism 225 comprises a valve bushing 243 mounted inthe same bore in the valve block I53 in which the valve bushing 228 isdisposed. The said bushings 228 and 243 are separated .by a disc .244through which is formed a port 245, the port 245 being utilized forconnecting the chambers formed at theadjacent of. the bushing 243.Disposed within the bore through the bushing 243 is a pilot valve member2561which has formed thereon piston portions -25I, 252 and 253, formingbetween them cannelures 254 and 255 for connectingthe pilot valvebushing radial ports in different combinations. As stated above, thereversing valve bushing 228 and pilot valve-bushing 243 are eachprovided with a chamber at their inner adjacent ends,

' being respectively formed on opposite sides of the disc 244. At thesame time the bushing 228 has a chamber 21] formed at its other endwhich is closed by a-plug 212 threadedinto the outer end thereof. Alsothe pilot valve bushing 243 is likewise provided with a chamber 213formed at its outer end, which chamber is closed by a plug 214. Theinner chamber of the pilot valve bushing communicates with the cannelure254, see Figure 22, by way of a port 215 formed centrally through thepilot valve member from the left hand end thereof as seen 'in the saidFigure 22.

and a transverse port 216 formed through the reduced portion of thevalve member which forms the cannelure 254. Likewise the chamber 213 atv the outer end of the pilot valve bushing communicates with thecannelure 255 by way of a port 211 formed centrally of the pilot valvemember from the left hand end thereof and a transverse port 218 formedthrough the reduced portion of the valve. member which forms thecannelure 255.

The pilot valve member has two operative posltions determined bycircumferential grooves 256 and'251 formed circumferentially of thevalve member 256 which co-operate with a spring loaded detent 258. Inorder to shift the valve there is provided a valve shifter member 259having a nose 268 disposed in a circumferential groove associated withthe valve member and forming shoulders at each end thereof against whichthe nose engages for shifting the-same. The shifter member 259 is pinnedor otherwise securedto a rod 266A mounted for sliding movement inbearings provided by the support ribs I69 of the housing I28.Intermediate its ends the rod 260A has formed therein a notch 26Ireceiving the ball end 262 of an arm 263, keyed or otherwise secured toan oscillatable shaft 264; The shaft 264 is journaled for oscillation ina bearing sleeve 265 supported by the housing rib 2I5 and the shaft 264projects beyond the sleeve 265 to which is secured a flipper member 266having depending fingers 261 and 268..

The pilot valve member 250 is adapted to be shifted to its differentpositionsat each end of the stroke of the carrier I40 for effecting thereportions of the dogs 269 and 210, however, are 1 offset. with respectto the operating portion of the stop dog 2| 1. Therefore, nointerference is had between, the said reversing and stop dogs and theflippers 266 and 2I6. From the foregoing it is believed now evident thatthe reverse reciprocations of the carrier I46 areeffected at each end ofthe travel of the carrier and since, as above described, the carrier isstopped at the completion of each complete cycle the mechanism is asemi-automatic one-or fully automatic when once set in motion.

Referring again to Figure 22 and continuing the description of thehydraulic circuit the ports' 229 of the reversing-valvebushingi haveconnected therewith one end of a conduit 219 which ter-, minates at itsother end inthe ports 248' of the pilot valve bushing. The ports 236 ofthe reversing valve bushing have connected therewith one terminus of apipe or conduit 280 which termi-.

nates atits other end in a pressure balancing valve mechanism indicatedgenerally bythe numeral 28I and the conduit 289 through the branchconduit 282 terminates at the right hand end of the wedge actuatingcylinder I43. The ports 23I have connected therewith the other end ofthe pressure conduit 222, which entends from the start and stop valvemechanism I5l while the ports 234 have connected therewith the other endof the branch discharge conduit 226 which likewise extends from thevalvemechanism I5I. The ports 232 have connected therewith one end of apipe or conduit 283 which terminates in the feed rate control valvemechanism indicated generally by the reference numeral 284, while theports 233 have connected therewith one end of a conduit 285 which inturn connects with conduits 286 and 281 respectively terminating in thefeed rate control valve mechanism and the left hand end of the wedgecylinder I43. The ports 235 have connected therewith one end of aconduit 288 which terminates at its other end in the pressure balancingvalve mechanism 28L The inner chamber of the reversing valve bushing andthe adjacent or inner chamber of the pilot valve bushing are showndiagrammatically in Figure 22 as connected by a line or conduit 289, butin practice this connection is made by way of the port 245 through theseparator disc as above described.

Referring now to'the remaining connections of the pilot valvebushingports, it will be seen that the ports 246 and 248 haverespectively connected therewith one end of conduits 299 and I29I whichempty into a conduit 292, in turn emptying into a conduit 293 whichterminates in the sump or tank I41. The ports 24! have connectedtherewith the other terminus of the return conduit 224 extending fromthe starting and stopping valve mechanism II.

The feed rate control valve mechanimn is shown structurally in Figure 19and is supported by the valve block I53 in which the starting andstopping valve, reversing valve and pilot valve are disposed. This feedrate control valve mechanism comprises a valve bushing 294 through whichis formed a plurality of sets of ports 295, 296 and 297, the latterbeing considerably elongated as compared to the others, each set,however, being encircled by a similar circumferential groove 298 formedin the exterior of the bushing 294. Disposed in the bore through thebushing 294 is a piston type valve 299 having formed thereon pistonportions 399, 39I and 392, forming between them cannelures 393 and 394.The central or piston portion 39I is utilized, dependingupon itsposition relative to the elongated ports 29?, to determine the rate ofhow of the medium from the cylinder I43 and thereby determine andcontrol the rate of movement of the piston therein and rate'of mofementof the work toward the wheel;

The valve member 299 is constantly urged to move toward the right, asseen in Figures 19 and 22, by a spring 395 which abuts on the rear endof the valve member 299 and on the base of an. enclosing sleeve 396carried by the valve bushing 294. The movement of the valve 399 by thespring 395 is limited by an adjustable abutment 391 carried by the endof a rod 398lying in axial alignm'entwith the valve member 399. The rod398 is mountedior sliding movement through -.bearings provided by thetransverse supporting ribs I69. The rod 398, and consequently the valvemember 399, are shifted automatically during the operation of themachine.

To efleot this axial shifting of the rod398 it is provided intermediateits ends with a transverse slot 399 receiving the ball end 3) of a lever3II keyed or otherwise secured to a shaft 3I2; The shaft 3I2 is disposedtransverselyof the housing I28 and is journaled for oscillation in asleeve 3I3 supported by the wall 2I5 of said housing. The shaft 3I2extends beyond the rear end of this supporting sleeve 3| 3 and to thesaid projection is pinned or otherwise secured a lever 3 which at itsouter end a roller 3I5. The roller 3I 5 rides on the cam face 3I6 of acam plate 3" which is secured to the carrier I49.

As seeninFigureS thecamface 3I6 of the cam plate 3" has a high Portion3I8 at its right hand end followed by a relatively rapid inclinedportion 3I9 and a low flat portion 329. When the roller 315 is on thehigh portion 3I8 the valve shifts under influence of the spring 395 toslow down the rate of movement of the work and when the roller reachesthe low level 329 this rate of movement is reduced to the usual rate ofinfeed or plunge cut grinding. The parts are so related to one anotherthat the roller 3! reaches the junction of the inclinations 3I9 and 329at substantially the same instant that the work initially contacts withthe grinding wheel. From then on the rate of movement of the workrelative to the wheel is at a constant grinding rate as above indicated.It is understood that this rate of movement refers to the infeed cammember I39 which acts through the plunger I26 and connecting links foroscillating the bed plate 97.

As seen in Figure 22 the feed rate valve bushing ports 295 haveconnected therewith the other end of the conduit 283 which extends fromthe reversing valve mechanism 223, whilethe ports 29? are also connectedwith the said conduit 283 by-means of a branch conduit 32L The ports295, in addition, have connected therewith one end of a conduit 322which terminates in the balanced pressure valve mechanism 28!, while theports 29! and 298 are additionally respectively connected by conduits323 and 324 which also terminate in the balanced pressure valve 28 l.

The balanced pressure valve is shown'structurally in Figure 19 and isutilized, as above noted, 'for' maintaining a definite back pressure inthe exhaust side of the system. This back pressure valve mechanism isactuated and controlled by the forward and exhaust pressures in thesystem and acts inconjunction with the feed rate control valve formaintaining the rate. of feed in accordance with the setting of the feedrate valve.

As shown in Figure 10, the balanced pressure valve is mounted in thesame valve block I 53 and for convenience is disposed beneath the feedrate valve mechanism. This balanced valve mechanism comprises a valvebushing 325 having formed therethrough a plurality of sets of radialports 326, 327, 328, 329 and 339, each set being connected by a similarcircumferential groove 33L Disposed within the bore through the bushing325 is the balanced valve member 332 having formed thereon pistonportions 333, 334 and 335 between which is formed cannelures 336 and331. The ends of the bushing bore are enlarged to'form the chambers 338and 339 into which the ends-of the valve member 332 project. The saidchambers are closed by means of plugs 349 and MI threaded into the endsof the bushing. It is intothe chambers 338 and 339 that the ports 339and 326 empty.

As seen in Figure 22 it is with the ports 32! that the conduit 322connects at its other end, while the conduits 323 and 324 connect withthe ports 339. The ports 326 are connected through a efiect and controlthe movement of the infeed wedge piston I42 which effects the actualmovement of the work as respects the grinding wheels. The completeoperation of this circuit is as follows:

The work piece is inserted within the grinding throat by means to besubsequently described into engagement with the work rest blade NH andthe lever 193 actuated to shift the starting and stopping valve memberIGI to its open position,.that shown in Figure 22. The valve is held inthis position manually until the latch 295 drops into locking positionbehind the collar 203. At this time the pilot reversing valve member 205is in the position opposite to that shown in Figures 9 and 22, therebyin effect causing the bed plate to be furtherretra'cted from thegrinding wheels, this for a reason which will be explained later. Thisretracting movement, however, takes place only for an instant when thereversing dog 210,

which at this time is adjacent the arm 261 of the flipper 296, engagessaid arm 28! for actuating the flipper 285 in a clockwise direction asseen in Figure 8, and thereby shifting the pilot valve member 259 to theposition shown in the drawings. 2

The flow of the hydraulic medium when the valve member 16! is firstshifted is through the conduit i50, starting and stopping valvemechanism hit, conduit 222, reversing valve 223, and conduit 280 to theright hand end of the cylinder M33 as seen in Figure 22 for actuatingthe piston M2 to the left thereof.. The medium ahead of only for a veryshort space. of time when the dog 2T9 shifts the pilot valve mechanism225 to the position shown in the drawings. The shifting of the pilotvalve opens up the chamber 248. at the right hand end thereof, therebypermitting a flow of the exhaust medium under pressure through theconduit 222, radial port 273 in the pilot valve member 259 and axialport 217 into the chamber 298'. The flow from the chamber 248' isthrough the conduit 219 to the chamber 2ll at the left hand end of thereversing valve member for'shifting it to the position shown in Figures9 and 22. The shifting of the reversing valve therefor disconnects theconduits 222 and 289 and connects instead the conduits 222 and 283,causing the flow of the medium to the feed rate valve mechanism 284.

Atthis time the feed rate valve member is to the opposite extremeposition from that shown in Figures 10 and 22 due to the fact that theroller 3 l 5 of the arm 3M, which controls the position of the valvemember 299, is riding on the high portion 318 of the cam 3 l I. Asexplained above, this permits a relatively free rate of flow in thesystem wherefore the piston [42 travels at a rapid rate to effect therapid approach of the'w'ork and grinding ,wheel. The continued movementof the piston I42 shifts the cam 3l'l whereupon the roller 288 ridesdown the inclined portion 3l9 to gradually shift the feed rate valvemember 299- to the position shown in the drawings for thereby slowingdown the rate of approach of the work and the grinding wheels. The flowof the tion to its port 297.

pressure valve member 332 to take a position i hydraulic medium whenactuating the work toward the grinding wheel is through the conduitsport 291 is relatively wide open so that the full flow is through thesaid port 291 to the port 296 and conduit 286, thereby obtaining therapid approach of the work and wheel. As the piston portion 3M on thevalve member 299 approaches. the closing off position shown in thedrawings, as above described, the flow through the port 291 is graduallydecreased, thereby gradually slowing down the movement of the piston.The unused and wasted medium passes through the port 29'? on the lefthand side of the piston portion 39! of the valve member 299- where it isconnected by the conduit 322 with the balanced pressure valve mechanism28!.

In order to maintain the feed or rate of move-' ment of the work withrespect to the wheel as determined by the position of the feed ratevalve member'299 the balanced pressure valve mechanism 281 is employedas above indicated. It will be noted that the forward pressure throughthe conduit 283 is connected by way of conduits 322 and 326 includingthe choke 343 with the chamber 339 at the left hand end of the balancedpressure valve member 332 and by way of conduits 321 and 323 with thechamber 338 at the right hand end of balanced valve member 332. Sincethere is normally no outlet frbm these chambers the pressures thereinwill be in accordance with the divided flow from the pressure conduit283 as eifected by the piston portion 30! of the balanced pressuremember 299 with rela- This causes the balanced relative to the port 328to permit the flow of the exhaust medium through the conduits 282 and286 through the balanced pressure valve member 332 and the conduit 288.During a grinding or tooling operation the piston portion 381 of thefeed control valve member 299 will be nearer the right hand end of theport 291. Since the feed is necessarily a low one the greatest flow ofthe medium from the conduit 283 will be through the port on the lefthand side of said piston portion 30!. In the event of an increased flowthrough the system or an increased pressure due to any of a number ofwell known reasons encountered in hydraulic circuits of machine tools,the increased flow would tend to accelerate the feed above thatestablished by the feed rate valve mechanism 284. This accelerationwould be substantially instantly checked because the increased flowwould be through the conduits 322 and 392 intothe chamber 339 andthereby shift the balanced valve member to the right forcutting down theexhaust flow from the cylinder may be accurately controlled. The workand until the dog 269 engages the second arm 268 on the flipper 266 forshifting the pilot valve member I6I to its second position which is, asabove noted. opposite to that shown in the drawings. This, of course,disconnects the conduits 224 from the radial port 218 and airial port211 and instead connects the said conduit 224 with the radial port 216and axial port 215 for thereby placing the chamber at the inner end ofthe pilot valve member under pressure; This pressure is iminediatelycommunicated through the port 245 of the. disc 244, as shown in Figure9, orthe conduit 289, as shown in Figure 22, with the inner chamber ofthe reversing valve member 231 and thereby shifting said valve member toits second or reversing position which is opposite to that shown in .thedrawings. At this time the flow of the hydraulic medium is that as firstdescribed.

This, of course, causes the piston I42 to travel to the left as seen inthe drawings. The movem'ent of the piston I42 in a retracting directionor to the left continues until the work is fully retracted to itsinitial position. As will be appreciated, this movement could beautomatically reversed by the reversing dog 210 engaging the arm 261 ofthe flipper 266, but before this occurs the cycle is stopped. Thisstopping is effected by the dog 2I1 which is set to engage the flipperdogv 2I-6 before the'reversing dog 210 actuated the flipper 266. Theactuation of the flipper dog 2I6 in a. clockwise directioncorrespondingly shifts the lever 2| I on the other end of the shaft to;which the flipper dog is secured. This movement of the lever 2IIactuated the latch 205 in a counterclockwise direction for lifting thenose 294 thereof above the collar I14 on the starting .and stoppingvalve stem I68. Upon release of the stem I68 the spring "I expands andshifts the starting and stopping valve to the stop position which is atthe other end of its movement from that shown in Figures 9 and 22 Uponstopping of the machine cycle the work piece is removed and .an'unfinished one substituted therefor, whereupon the lever I94 is, againengaged for initiating the cycle of the machine. The means for insertingand withdrawing the Work into and from the grinding throat isillustratedin Figures 3, 18, 19 and 20. As there shown,

341. The said brackets 349 and 358 are each provided with an elongatedaperture 35I through V which passes attachment bolts or studs 352 intosaid side bars.

Thework is adapted to be'shifted relative to -the work supporting framefor which purpose there is provided atransverse member 353 convenientlytaking the-form of an angle iron secured in any desirable manner to endplate members 354.- The angleiro'n 353 and plates 354 are shifted belowthe supporting frame and have secured thereto at opposite ends thereofbrackets 355 and 356. Intermediate the-ends of the angle iron 353 itcarries a plurality ofcradle blocks 351 having formed therein slots 358in which the work is disposed and whereby the said work is moved v withthe plates 354 and angle iron353.

v 2,065,100 tool would be actuated relative to one another In order toeifect the movement of the angle iron 353, and therefore, the work, thebrackets 355 and 356 at the opposite ends of the said angle iron arerespectively secured to endless sprocket chains 359 and 369. The saidchains 359 and 368 are each trained about a pair of sprockets 36! and362 located at opposite ends of the side bars 346 and 341. Thesprockets'36I are each journaled in a block 363 disposed at the inner ends of theside bars 346, while the sprockets 362 are each journaled in blocks 364disposed at the outer ends of the said side bars 346 and 341. Inpractice, the outer sprockets 362 are keyed or otherwise secured to ashaft 365 which is in turn rotatably journaled in the blocks 364.

Additionally, each of the shafts 365 have secured to them a small rackpinion 366 respectively in mesh with rack teeth 361 and 368 of a rackbar 369. The rack bar 369 is mounted in suitable bearings provided bythe forward frame bar 344 for sliding movement relative thereto and theteeth thereof upon sliding movement effect a rotation of the rackpinions 366 for actuating the endless sprocket chains 358 and 359 in thesame direction, which causes the angle bar 353 and its plates 354 tomove toward or from the-grinding throat.

In order to effect the sliding movement of the bar 369 the outer framemember 344 is provided witha lug 316 in which is journaled at 31I oneend of a lever 312. The outer end of the lever 312 is provided with anoperating handle or knob 313 and between the said handle a pivot point31I with a lug 314 A link 315 has one end pi oted at 316 to the leverlug 314 and has its other end pivoted at 311 to the rack bar 369intermediate the ends of said bar. The coupling of the link 31".) withthe lever 312 is such as to provide a self-evident since by grasping thehandle 313 of the lever 312 and actuating same in a'clockwise directionwill shift the link 315 and therefore the rack bar 369 to the rightcausing a clockwise rotation of the right hand outer sprocket 362 and acounterclockwise rotation of the left hand outer sprocket 362, therebycausing the angle iron 353 to be withdrawn from the grinding throat.Naturally an opposite actuation of the parts would reversely shift thework cradles and work'carried thereby.

In order to limit the inward movement of the work and insure thatthesame is positioned properly within the grinding throat the brackets 355and 356 are each provided with an adjustable abutment screw 318 and 319which engage with the wall of the sprocket supporting blocks 363. Thework is held yieldably against the Work rest blade I9I during thegrinding operation, for which purpose the work rest blade block I06 hassecured hereto at several points and along its length a bracket 380 towhich is pivotally mounted at 38I a bell crank 382. The bell crank 392has rotatably journaled at one end of one of its arms a pressure roller383 and at the outer end of its second arm an abutment lug 384. Theabutment lug 384 is adapted to be engaged by a spring actuated plunger385 yieldably urged relative to a bracket 386 carried by the angle iron353 and disposed at points along said angle'iron intermediate the workcradles351. From the foregoing it will be noted that when the work isinserted within the grinding throat. the carriage therefor through thespring plunger carried thereby will yieldably hold the work against thework rest blade during the grinding operation.

The grinding and regulating wheels must peri odically be trued in orderto produce accurate work pieces having the desired quality of finish.

.The means for truing the grinding wheels and ures 3, 11, 12, 13, 14 and22, the latter figure showing the hydraulic circuit and its connectionwith the machine circuit.

The'truing mechanism comprises a housing 38! provided with a dovetailguideway 383 receiving a correspondingly shaped tongue 389 formed ontheunder surface of a slide. or carriage 390 which supports the truingmechanism indicated generally bythe numeral 39l. The truing mechanism39l comprises a sleeve 392 mounted in a cylindrical boss 393 integralwith a second slide 39'l mounted on and transversely shiftable relaatits inner end the diamond or truing tool 395;

The outervend of the bar 392 has a threaded bore tive to the slide 399.Mounted in the sleeve 392 is the truing tool or diamond bar 394 carryingtherein receiving the threaded end of a screw 396 whereby the said baris axially adjusted relative to the surface of the wheels for effectingthe inward movement thereof.

As will be noted from the left hand end of Figure 11 one of the grindingwheels, 3614, is of a smaller diameter than the other wheels, however,each of the wheels have a plane face. In order ,to insure the wheelsbeing trued with a plane face the upper slide 391 of the truingmechanism has its position controlled by a cam. The cam is shown inFigure 11 and comprises a cylindrical bar 398 having secured thereto orformed integral therewith a plurality of cylindrical spools 399, 400 and40! which are respectively disposed in alignment with one of thegrinding-wheels. The bar 3913, together with the cam portions thereon,is mounted in brackets 402 secured to a ledge or shelf 493 projectingoutwardly from the mairrsupporting bracket 381. In order to true theface of the smaller wheel 36A thacam sleeve 4M is provided with a.reduced portion or second cam face 404. Secured to the outer end of theupper slide 391 is a stud 495 rotatably carrying a roller 408 whichcontacts with the periphery of the cam portions on the bar 398. In orderto maintain engagement of the roller406 and the controlling cam portionsthe traversing or lower slide 390 is formed with a lug 49! forming oneabutment for a spring 498 which abuts at its other end with the lug 409,depending from the upper slide 391.-

The said spring 438 tends to shift the said upper carriage toward theface of the wheels and thereby maintains contact between the followerroller 406 and cam portions 399, 400, Ml and 4ll4. From this it willfollow that the said cams absolutely determine the operative position ofthe truing tool or diamond 395 while cutting across the piston M2. Thepiston M2 is secured to the inner end of a hollow piston rod 3 whichpasses out through a head 4 on one end of the said cylinder 4| I. Theouter end of the hollow piston rod 3 is secured in a block 415 carriedby the bracket 3". Extending through the hollow piston rod 413 is a pipeor tube 6 likewise having its outer end anchored'in the block' 415. Thepiston rod 3 communicates with the cylinder on one side of the piston 2through suitable ports 4I'I formed therein, while the pipe or tubewithin the piston rod communicates with the cylinder on the other sideof the piston H2. The anchoring block 5 communicates with the reversingvalve mechanism illustrated in Figure 14 for alternately connecting thehydraulic medium under pressure with the opposite sides of the pistonand thereby effecting reverse reciprocations of the truing tool relativeto the wheels.

The hydraulic circuit is shown in Figure 22 and as there shownillustrates similar mechanism for each of the truing mechanisms, thatis, the mechanism for the grinding wheels and the mechanism for theregulating wheels. It will further be seen that when one of the truingmechanisms is being used the other is inoperative since the ,idleposition of the first truing mechanism connects the pressure medium withthe secondtruing mechanism. Since, however, the control mechanisms forthese truing mechanisms are otherwise identical but one of them will bedescribed in detail as will the coupling between the two. 7 Accordinglythe supply line 221 which extends from the starting and stopping valvemechanism l5| terminates at the reversing valve mechanism 4i8,diagrammatically shown in Figure 22 and structurally shown in Figure 14.The valve mecha nism as shown in Figure 14 comprises a casing 9 in whichis pressed a valve bushing 42!! having formed therethrough a pluralityof sets of radial ports 42l, 422, 423, 424, 425, 426, 42'! and 428, eachset being encircled by a similar circumferential groove 429 formed inthe exterior of the bushing 420. Disposed within the bore in the bushing420 is a valve of the sliding piston type 430, having formed thereonpiston portions 43l, 432 and 433, forming between them cannelures 434,435 and 436 for connecting in different combinations the radial ports inthe bushing 420, depending upon the position of the valve member 430.

The valve member 430 has three operative positions and in order to shiftthe valve to said positions it is provided therein with a transverseslot 431 in which is received the ball end 438 of a valve shifter 439pinned or otherwise secured to an oscillatable, slidable shaft 440. Todetermine the operative positions of the valve member 430, the shaft 448has fastened to it a dog 44! provided in its outer periphery withnotches 442. Co-operating with the said notches is the nose 443 of aspring pressed detent 444.

The shaft 440 is mounted for sliding and oscillatory movement inbearings 445 provided by the valve housing 9. The outer end of the shaft440 projects beyond the housing 4 l 9 to which is pivotally secured ahandle 446. The lower end of the handle 445 is provided with a ball 44'!disposed in a slot 448 formed ina block 449 secured to the housing 9.The handle 446 is oscillated toward and from the housing 9 about thehorizontal axis of its ball 44? in order to efl'ect the sliding As seenin Figure 22 the supply conduit 221 connects through branch conduits 456and 45l. with the ports 423 and 426 of the reversing valve mechanism418. The ports 428 have connected therewith one end of a dischargeconduit 45IA which terminates at its other end in the discharge conduit226 below the back pressure valve 22L The port 421 by one truingmechanism has connected therewith one end of a. conduit 452 wnichterminates at its other end in the reversing valve mechanism 453 of thesecond truing mechanism and thereby, supplies pressure to said mechanismwhen desired. At the same time the reversing valve mechanism 453, whenneither of the truing mechanisms are in use, connects the conduit 452with a conduit 454 which has its one end' terminating inthe saidreversing mechanism, and its other end terminating in the dischargeconduit 45|A and thereby shorts the system on itself. The ports 42l and425 of. the reversing valve bushing 426 have respectively connected withthem one end of conduits 455 and 455 which in turn empty into a conduit451 that terminates in a rate control valve indicated generally by thenumeral 458. The remaining ports 422 and 423 have respectively connectedtherewith one end of and shaft. 446 for opening the ports 464 andpermitting a greater flow through the ports 464. Referring again toFigure 22 it will now be appreci'ated that the conduit 451 from thereverse valve mechanism M8 is the exhaustconduit and is connected withthe ports 464 of the rate control valve 458. The remaining ports 463 and462 of this rate control valve 458 are respectively connected with oneend of conduits 483 and 464 which in turn empty into a conduit 485discharging into the main return conduit 45IA.

The stem 412 which controls the closing off position of the rate controlvalve 466 isset to determine the rate of movement of the truing toolpast the wheels. By reference to the drawings, it will be seen that thewheels are spaced a considerable distance apart and if the rate oftravel of the truing tools between the said wheels were maintained atthe truing speed a considerable amountof lost time would ensue. For thisreason the valve member 466 is automatically, axially positioned toincrease the rate of travel of the'tool between the wheels. To effectthis increase in this rate of travel and to automatically adjust theposition of the rate valve member 466, the shaft 411 extends beyond thehousing conduits 459 and 466, which respectively connect 4H! as a splineshaft 486. This shaft 486 extends at their opposite ends with the hollowpiston rod and the pipe extending therethrough for alternately supplyingthe pressure to opposite sides of the piston 4| 2 and connecting theremaining side to the sump or tank.

The rate control valve is illustrated structurally in Figure 12 andcomprises a valve bushing 46l having formed therethrough a plurality ofsets of radial ports 462, 463 and 464, each set being connected by asimilar circumferential groove 465 formed in the exterior of the bushing46!. Mounted within the bushing 46I is the rate control valve member 466having formed substantially at opposite ends piston portions 461 and468, forming between them the cannelure 469.

The piston portion 468 is provided at its inner end with a conicalportion 416 which acts as an hydraulic resistance to more or less limitthe flow of the hydraulic medium through the ports 464. The minimumamount of flow through the ports 464 as eifected by the conical portion416 may be adjusted by limiting the movement of the valve member 466 tothe left as seen in Figure 12. This adjustment is effected by anabutment 4" formed on the inner end of a stem 412 threaded into a bonnet413 in the end of the valve bushing 4J6l.

The .valve member 466 may be manually positioned with respect to itsbushing 46l by means of the handle 446 and axial shifting of the shaft446 For this purpose the shaft 446 has formed therein a transverse notch414 receiving the upper ball end 415 of a lever 416 keyed or otherwisesecured to a shaft 411. The lower end of the lever 416 is also providedwith a ball end 416 received in a notch 416 formed in the valve member466. By reference to Figure 12 it will, therefore, be seen thatactuation of the shaft 446-in an axial direction will oppositely shiftthe valve member 466. The valve member 466 is normally shifted to itsclosed position, that illustrated in Figure 12, for which p pose theshaft 411 has keyed or otherwise secured to it an am 466 to the free endof which is secured a spring 461 having its other end anchored in afixed part of the valve housing 419, such as the pin 482 projecting froma wall thereof. From this it is seen that the rate control valve member466 is manually operated or actuated through the handle 446 entirelyacross the machine and the wheels thereof. Secured to the underside ofthe lower slide 396 is an arm 481, see Figure 3, having oscillatablymounted therein a sleeve 488. The sleeve 488 has a splined boretherethrough complemen-.

cured to the shelf or ledge 463 projecting from the housing 381. The cambar 492 is provided with a plurality of enlarged cam portions 493 whichact on the cam follower for shifting the arm 496 in a counterclockwisedirection as seen in Figure 3, thereby correspondingly oscillating orrotating the shaft 486 411. The oscillation of the shaft.correspondingly actuates the lever 416 for shifting the rate controlvalve to a position for opening the exhaust ports 464 and permitting anincrease in rate of travel of the truing tool. As will be seen fromFigure 11, the cam portions 493 are located intermediate the grindingwheels 36 so as to increase the speed of travel I toward and from thegrinding wheel, hydraulical- 'ly actuated means for effecting theoscillation of the unit, and control means for the hydraulic actuatingmeans for cyclically oscillating the unit at a rapid rate and a slowrate toward the grinding wheel, .and at a .rapid rate from the grindingwheel and stopping said oscillation in the retracted position.

- 2. In a centerless grinding machine the combination of a bed, agrinding wheel rotatably mounted on said bed, an opposed regulatingwheel forming with the grinding wheel a grinding throat, a headrotatably supporting the regulating wheel, a slide for the head," asupporting plate pivotally mounted on the bed for the slide, and meanspivotally connecting the slide pivot means to the bed whereby the platemay be adjusted transversely of the bed for aligning the axes of thegrinding and regulating wheels and whereby the plate may be oscillatedto effect a relative approach and retraction of the grinding andregulating wheel axes.

3. In a centerless grinding machine the combination of a bed, a grindingwheel rotatably mounted on said bed, an opposed regulating wheel formingwith the grinding wheel a 'grinding throat, a head rotatably supportingthe regulating wheel, a slide for the head, a supporting I platepivotally mounted on the bed for the slide,

means pivotally connecting the slide pivot means to the bed whereby theplate may be adjusted transversely of the bed for aligning the axes ofthe grinding and regulating wheels and whereby the plate may beoscillated to effect a relative approach and retraction of the grindingand regulating wheel axes, and power actuated means for eiiecting theoscillation of the plate toward and from the grinding wheel.

4. In a centerless grinding machine the combination of a bed, a grindingwheel rotatably mounted on said bed, an opposed regulating wheel formingwith the grinding wheel a grinding throat, a head rotatably supportingthe regulating wheel, a slide for the head, a supporting plate pivotallymounted on the bed for the slide, means pivotally connecting the slidepivot means to the bed whereby the plate may be adjustedtransversely ofthe bed foraligning the axes of the grinding and regulating wheels andwhereby the plate may be oscillated to effect a relative approach andretraction of the grinding and regulating wheel axes, power actuatedmeans for effecting the oscillation of the plate toward and from thegrinding wheel, means within the grinding throat for peripherallysupporting a work piece, a second slide on the plate for supporting thework supporting means, and independent means for efiecting theadjustment of the said slides for varying the grinding throat and theposition of the work'support relative thereto.

5. In a machine tool organization the combination of a bed, a platepivotally secured to the bed, a slide member mounted on the plate formovement relative thereto, a wedge shaped cam for efiecting theoscillation of the plate, an hydraulic piston and cylinder mechanism foractu ating the cam, and control means forsequential- 1y shifting the camat rapid and slow rates in one direction and at a rapid'rate in thereverse direction.

6. In a machine tool organization the combination of a bed, a platepivotally secured to the bed, a slide member mounted on the plate formovement relative thereto, a wedge shaped cam for eflecting theoscillation of the plate, an hydraulic piston and cylinder mechanism foractuating the cam, control means for sequentially shifting the cam atrapid and slow rates in one direction and ata rapid rate in the reversedirection, and manual means for initiating the operation of the pistonand cylinder mechanism.

7. In a machine tool organization the combination of abed, a platepivotally secured to the bed, a slide member mounted on the plate formovement relative thereto, a wedge shaped cam for efiecting theoscillation of the plate, an hydraulic piston and cylinder mechanism foractuating the cam, control means for sequentially shifting the cam atrapid and slow rates in one direction and at a rapid rate in the reversedirection, manual means for initiating the operation of the piston andcylinder mechanism, and automatic means for stopping the operation ofthe piston and cylinder mechanism at the end of the reverse rapidmovement.

8. In a machine tool organization the combination of a bed, a toolsupport, a work support, means pivotally connecting one of said supportsto the bed for oscillation relative thereto toward and from the tool,cam means for effecting the oscillation of the said support, anhydraulic motor for actuating the cam, an hydraulic circuit forcontrolling the movement of the motor including a start and stop valve,manual means for shifting the start and stop valve in one direction,yielding means for shifting the said start and stop valve in the otherdlrection,means for latching the valve in the position eiiected by themanual means, automatically operable means for unlatching the valve topermit its operation by the yielding means, a pressure actuatedreversing valve between the starting and stopping valve and motor, and apilot valve operated by the motor for connecting the hydraulic pressurewith the reversing valve to effect its operation.

9. In a grinding machine the combination of a bed, a grinding wheel headmounted thereon, a work head mounted on the bed, a support for one ofsaid heads pivotally secured to the bed for oscillation toward and fromthe other head, a wedge cam for efiecting the oscillation of said headsupport, a connection between the cam and support whereby movement ofthe cam effects the oscillation of the support, an hydraulic motor foractuating the cam, an hydraulic circuit for efiecting the operation ofthe motor, astarting and stopping valve in said circuit for initiatingand stopping the operation of the motor, a rate control valve in thecircuit for determining the rate of movement of the motor and rate ofoscillation of the support, and means operable by said motor forautomatically positioning the rate control valve to automaticallydetermine and vary the rate of operation of the motor.

- 10. In a grinding machine the combination of a bed,a grinding wheelhead mounted thereon, a work head mounted on the bed, a support for oneof said heads pivotally secured to the bed for oscillation toward andfrom the other head, a wedge cam for effecting the oscillation of saidhead support, a connection between the cam and support whereby movementof the cam efiects the oscillation of the support. an hydraulic motorfor actuating the cam, an hydraulic circuit for efiecting the operationof the motor, a starting and stopping valve in said circuit forinitiating ping valve to initiate the operation of the motor.

11. In a grinding machine the combination. of a bed, a grinding wheelhead mounted thereon, a work head mounted on the bed, a support for oneof said heads pivotally secured to the bed for oscillation toward andfrom the other head, a wedge cam for effecting the oscillation of said

